<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width,initial-scale=1.0 minimum-scale=1, maximum-scale=1"" >
    <link rel="icon" href="<%= BASE_URL %>favicon.ico">
    <title><%= htmlWebpackPlugin.options.title %></title>
  </head>
  <body>
    <noscript>
      <strong>We're sorry but <%= htmlWebpackPlugin.options.title %> doesn't work properly without JavaScript enabled. Please enable it to continue.</strong>
    </noscript>
    <div id="app"></div>
    <!-- built files will be auto injected -->
  </body>
<script>
  (function (designWidth, maxWidth) {
    var doc = document,
            win = window,
            docEl = doc.documentElement,
            remStyle = document.createElement("style"),
            tid;

    function refreshRem() {
      var width = docEl.getBoundingClientRect().width;
      maxWidth = maxWidth || 540;
      width > maxWidth && (width = maxWidth);
      var rem = width * 100 / designWidth;
      remStyle.innerHTML = 'html{font-size:' + rem + 'px;}';
    }

    if (docEl.firstElementChild) {
      docEl.firstElementChild.appendChild(remStyle);
    } else {
      var wrap = doc.createElement("div");
      wrap.appendChild(remStyle);
      doc.write(wrap.innerHTML);
      wrap = null;
    }
    //要等 viewport 设置好后才能执行 refreshRem，不然 refreshRem 会执行2次；
    refreshRem();

    win.addEventListener("resize", function () {
      clearTimeout(tid); //防止执行两次
      tid = setTimeout(refreshRem, 300);
    }, false);

    win.addEventListener("pageshow", function (e) {
      if (e.persisted) { // 浏览器后退的时候重新计算
        clearTimeout(tid);
        tid = setTimeout(refreshRem, 300);
      }
    }, false);

    if (doc.readyState === "complete") {
      doc.body.style.fontSize = "16px";
    } else {
      doc.addEventListener("DOMContentLoaded", function (e) {
        doc.body.style.fontSize = "16px";
      }, false);
    }
  })(750, 750);
</script>
</html>
